Clinical Study of LPI With Different Laser Wavelengths

Glaucoma Clinical Trial

Official title:

Clinical Study of Laser Peripheral Iridoplasty With Different Laser Wavelengths

Clinical Trial Details — Status: Active, not recruiting

Administrative data

• NCT number: NCT02901730
• Other study ID #: [2016]102-2
• Status: Active, not recruiting
• Phase: N/A
• First received: September 11, 2016
• Last updated: September 11, 2016
• Start date: September 2016
• Est. completion date: December 2017

Study information

• Verified date: September 2016
• Source: First Affiliated Hospital of Fujian Medical University
• Contact: n/a
• Is FDA regulated: No
• Health authority: China: Health and Family Planning Commission of Fujian Province
• Study type: Interventional

Clinical Trial Summary

Glaucoma is the second cause of blindness worldwide. Laser peripheral iridoplasty (LPI) is a simple and effective treatment for angle closure glaucoma. LPI can widen or reopen an existing angle close or angle adhesion in order to reduce the risk of attack of the angle closure glaucoma. However, there are very little research on the laser site, laser wavelengths, laser energy and laser spot intervals. The purpose of this study is to determine the optimum laser wavelengths of LPI.

Description:

Glaucoma is the second cause of blindness worldwide. Laser peripheral iridoplasty (LPI) is a simple and effective treatment for angle closure glaucoma. LPI can widen or reopen an existing angle close or angle adhesion in order to reduce the risk of attack of the angle closure glaucoma. However, there are very little research on the laser site, laser wavelengths, laser energy and laser spot intervals.Conventional LPI uses wavelength 532nm laser. However, our preclinical studies have found that the laser penetration of the laser wavelength 561nm is stronger than that of the laser wavelength 532nm. It can produce a stronger contraction effect.

The purpose of this study is to determine the optimum laser wavelengths of LPI. Baseline and 7days, 1 month, 3 months after LPI, the structure of anterior chamber, including angle anterior chamber depth(ACD), angle of anterior chamber (AA), anterior chamber angle opening distance 750(AOD750) are measured with ultrasound biomicroscopy. Baseline and 7days, 1 month, 3 months after LPI, the outflow resistance of aqueous humor are evaluated with C value. Baseline and 1hour, 1days, 3day, 7days, 1 month, 3 months after LPI, intraocular pressure are measured with Goldmann tonometry. Baseline and 3 months after LPI, retinal nerve layer thickness and the optic disc cup disc ratio are measure with optical coherence tomography.

Recruitment information / eligibility

• Status: Active, not recruiting
• Enrollment: 30
• Est. completion date: December 2017
• Est. primary completion date: December 2017
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 30 Years to 65 Years

Eligibility

Inclusion Criteria:

• Patients with primary angle closure suspect (PACS), primary angle closure (PAC) or primary angle closure glaucoma (PACG).

• PACS is diagnosed in eyes with an occludable angle but no other abnormality.

• PAC is diagnosed in eyes with an occludable angle, normal optic discs and visual fields and any of the following: raised IOP (>19 mm Hg), PAS, pigment smearing in the superior angle, or sequelae of acute angle closure (iris whirling or glaucomatous fleck).

• PACG is diagnosed in eyes with an occludable angle and glaucomatous optic neuropathy. Evidence of glaucomatous optic neuropathy is defined as a cup: disc ratio (CDR) of >0.7 or >0.2 CDR asymmetry.

• An occludable angle is defined as one in which three quarters of the posterior pigmented trabecular meshwork is not visible on viewing with a Goldmann two mirror lens in the primary position of gaze without indentation.

Exclusion Criteria:

• Patients with previous ocular surgery, and those with secondary angle closure, such as lens intumescence or subluxation, iris neovascularisation and a history of uveitis.

• Patients who have systemic contraindications to medical therapy (including renal impairment, sulfur allergy, asthma and heart failure), pre-existing corneal opacities obstructing laser access to more than one quadrant of the peripheral iris and single-eyed patients are also excluded.

Study Design

Allocation: Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Outcomes Assessor), Primary Purpose: Treatment

Related Conditions & MeSH terms

• Glaucoma

Intervention

Procedure:
• 532nm laser group
LPI with 532nm laser.
• 561nm laser group
LPI with 561nm laser.

Locations

Country	Name	City	State
n/a

Sponsors (1)

Lead Sponsor	Collaborator
First Affiliated Hospital of Fujian Medical University

References & Publications (8)

Fu J, Qing GP, Wang NL, Wang HZ. Efficacy of laser peripheral iridoplasty and iridotomy on medically refractory patients with acute primary angle closure: a three year outcome. Chin Med J (Engl). 2013 Jan;126(1):41-5. — View Citation

Lai J, Choy BN, Shum JW. Management of Primary Angle-Closure Glaucoma. Asia Pac J Ophthalmol (Phila). 2016 Jan-Feb;5(1):59-62. doi: 10.1097/APO.0000000000000180. — View Citation

Lee JR, Choi JY, Kim YD, Choi J. Laser peripheral iridotomy with iridoplasty in primary angle closure suspect: anterior chamber analysis by pentacam. Korean J Ophthalmol. 2011 Aug;25(4):252-6. doi: 10.3341/kjo.2011.25.4.252. Epub 2011 Jul 22. — View Citation

Marchini G, Chemello F, Berzaghi D, Zampieri A. New findings in the diagnosis and treatment of primary angle-closure glaucoma. Prog Brain Res. 2015;221:191-212. doi: 10.1016/bs.pbr.2015.05.001. Epub 2015 Jun 30. — View Citation

Mochizuki H, Takenaka J, Sugimoto Y, Takamatsu M, Kiuchi Y. Comparison of the prevalence of plateau iris configurations between angle-closure glaucoma and open-angle glaucoma using ultrasound biomicroscopy. J Glaucoma. 2011 Jun-Jul;20(5):315-8. doi: 10.10 — View Citation

Narayanaswamy A, Baskaran M, Perera SA, Nongpiur ME, Htoon HM, Tun TA, Wong TT, Goh D, Su DH, Chew PT, Ho CL, Aung T. Argon Laser Peripheral Iridoplasty for Primary Angle-Closure Glaucoma: A Randomized Controlled Trial. Ophthalmology. 2016 Mar;123(3):514- — View Citation

Sng CC, Aquino MC, Liao J, Zheng C, Ang M, Chew PT. Anterior segment morphology after acute primary angle closure treatment: a randomised study comparing iridoplasty and medical therapy. Br J Ophthalmol. 2016 Apr;100(4):542-8. doi: 10.1136/bjophthalmol-20 — View Citation

Wright C, Tawfik MA, Waisbourd M, Katz LJ. Primary angle-closure glaucoma: an update. Acta Ophthalmol. 2016 May;94(3):217-25. doi: 10.1111/aos.12784. Epub 2015 Jun 27. Review. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Change of anterior chamber angle(AA)	Anterior chamber angle (AA) is measured with ultrasound biomicroscopy.	Baseline and 3 months after LPI.	Yes
Secondary	Change of anterior chamber angle opening distance 750(AOD750)	Anterior chamber angle opening distance 750(AOD750) is measured with ultrasound biomicroscopy.	Baseline and 3 months after LPI.	Yes
Secondary	Change of anterior chamber depth(ACD)	Anterior chamber depth(ACD) is measured with ultrasound biomicroscopy.	Baseline and 3 months after LPI.	Yes
Secondary	Change of intraocular pressure (IOP)	IOP is measured with Goldmann tonometry.	Baseline and 1hour, 1days, 3day, 7days, 1 month, 3 months after LPI.	Yes
Secondary	Change of C value	IOP is measured with Schftz tonometry.	Baseline and 7days, 1 month, 3 months after LPI.	Yes
Secondary	Change of retinal nerve layer thickness	Retinal nerve layer thickness is measured with optical coherence tomography.	Baseline and 3 months after LPI.	Yes
Secondary	Change of optic disc cup disc ratio	Optic disc cup disc ratio is measured with optical coherence tomography.	Baseline and 3 months after LPI.	Yes
Secondary	Change of mean defect	Mean defect is measured with computer perimetry.	Baseline and 3 months after LPI.	Yes
Secondary	Change of mean sensitivity	Mean sensitivity is measured with computer perimetry.	Baseline and 3 months after LPI.	Yes
Secondary	Change of scotoma	Scotoma is measured with computer perimetry.	Baseline and 3 months after LPI.	Yes